This project is a continuation of a long range research program concerned with the effects of drugs and electrical stimulation of the brain on memory storage processes. The major objective is to obtain findings which will contribute to an understanding of the neurobiological process underlying memory storage. The basic assumption underlying the research is that the processes involved in memory storage are initially labile and susceptible to modification--either enhancement or disruption--for a period of time following an experience. The findings of previous research suggest that memory storage may be affected by arousal and associated changes in central catecholamine levels and hormonal levels. To investigate this possibility, one series of experiments will investigate the effects, on memory storage, of drugs which affect central catecholamine biosynthesis, storage, metabolism and reuptake. In addition, we are examining the effects, on memory, of peripherally administered hormone treatments. Another series of experiments will investigate the effects, on memory storage, of direct electrical and drug stimulation of specific subcortical brain regions. Our basic goals are to specify the experimental conditions under which these treatments modulate memory processes and to examine the neurobiological mechanisms by which the treatments act on memory processes.